must have+p.p.

phr

• ①[对于过去事情的推论]一定…过
  • How you must have loved her!你一定非常爱她吧!
  • I said he must have taken the wrong road.[间接引句]我说他一定是走错了路。

• ②[必要]
  • He must have stolen it!一定是他偷的!(参照He cannot have stolen it!不可能是他偷的!)
  • One must have lived long to see [before one can see] how short life is.人要长寿方知人生有多短。